CFS Definitions Over Time

March 14, 2012

Created by Wdb (Phoenix Rising Forums -2010)

The 1988 Holmes Definition for CFS -The earliest CFS definition

A case of the chronic fatigue syndrome must fulfill major criteria 1 and 2, and the following minor criteria: 6 or more of the 11 symptom criteria and 2 or more of the 3 physical criteria; or 8 or more of the 11 symptom criteria.

MAJOR CRITERIA

New onset of persistent or relapsing, debilitating fatigue or easy fatigability in a person who has no previous history of similar symptoms, that does not resolve with bedrest, and that is severe enough to reduce or impair average daily activity below 50% of the patient’s premorbid activity level for a period of at least 6 months.

If any of the results from these tests are abnormal, the physician should search for other conditions that may cause such a result. If no such conditions are detected by a reasonable evaluation, this criterion is satisfied.

MINOR CRITERIA

Symptom Criteria
To fulfill a symptom criterion, a symptom must have begun at or after the time of onset of increased fatigability, and must have persisted or recurred over a period of at least 6 months (individual symptoms may or may not have occurred simultaneously). Symptoms include:

Mild fever – oral temperature between 37.5 degrees C and 38.6 degreesC, if measured by the patient – or chills. (Note: oral temperatures of greater than 38.6 degrees C are less compatible with chronic fatigue syndrome and should prompt studies for other causes of illness.)

Sore throat.

Painful lymph nodes in the anterior or posterior cervical or axillary distribution.

Unexplained generalized muscle weakness.

Muscle discomfort or myalgia.

Prolonged (24 hours or greater) generalized fatigue after levels of exercise that would have been easily tolerated in the patient’s premorbid state.

Generalized headaches (of a type, severity, or pattern that is different from headaches the patient may have had in the premorbid state).

Description of the main symptom complex as initially developing over a few hours to a few days (this is not a true symptom, but may be considered as equivalent to the above symptoms in meeting the requirements of the case definition).

Physical Criteria

Physical criteria must be documented by a physician on at least two occasions, at least 1 month apart.

Additional requirements
The concurrent occurrence of four or more of the following symptoms, all of which must have persisted or recurred during 6 or more consecutive months of illness and must not have predated the fatigue:

Final requirement
All other known causes of chronic fatigue must have been ruled out, specifically clinical depression, side effects of medication, eating disorders and substance abuse.

The clinical evaluation should include:

A thorough history that covers medical and psychosocial circumstances at the onset of fatigue; depression or other psychiatric disorders; episodes of medically unexplained symptoms; alcohol or other substance abuse; and current use of prescription and over-the-counter medications and food supplements;

A mental status examination to identify abnormalities in mood, intellectual function, memory, and personality. Particular attention should be directed toward current symptoms of depression or anxiety, self-destructive thoughts, and observable signs such as psychomotor retardation. Evidence of a psychiatric or neurologic disorder requires that an appropriate psychiatric, psychological, or neurologic evaluation be done;

Other diagnostic tests have no recognized value unless indicated on an individual basis to confirm or exclude a differential diagnosis, such as multiple sclerosis.

Canadian 2003 criteria
Clinical Working Case Definition of ME/CFS
A comprehensive criteria favoured by many patients and organisations due to it clearly defining ME/CFS as opposed to other more general definitions of CF or CFS

A patient with ME/CFS will meet the criteria for fatigue, post-exertional malaise and/or fatigue, sleep dysfunction, and pain; have two or more neurological/cognitive manifestations and one or more symptoms from two of the categories of autonomic, neuroendocrine and immune manifestations; and adhere to item 7.

Fatigue: The patient must have a significant degree of new onset, unexplained, persistent, or recurrent physical and mental fatigue that substantially reduces activity level.

Post-Exertional Malaise and/or Fatigue: There is an inappropriate loss of physical and mental stamina, rapid muscular and cognitive fatigability, post exertional malaise and/or fatigue and/or pain and a tendency for other associated symptoms within the patient’s cluster of symptoms to worsen. There is a pathologically slow recovery period–usually 24 hours or longer.

Sleep Dysfunction:* There is unrefreshed sleep or sleep quantity or rhythm disturbances such as reversed or chaotic diurnal sleep rhythms.

Pain:* There is a significant degree of myalgia. Pain can be experienced in the muscles and/or joints, and is often widespread and migratory in nature. Often there are significant headaches of new type, pattern or severity.

Neurological/Cognitive Manifestations: Two or more of the following difficulties should be present: confusion, impairment of concentration and short-term memory consolidation, disorientation, difficulty with information processing, categorizing and word retrieval, and perceptual and sensory disturbances–e.g., spatial instability and disorientation and inability to focus vision. Ataxia, muscle weakness and fasciculations are common. There may be overload1 phenomena: cognitive, sensory–e.g., photophobia and hypersensitivity to noise–and/or emotional overload, which may lead to “crash”2 periods and/or anxiety.

The illness persists for at least six months. It usually has a distinct onset,** although it may be gradual. Preliminary diagnosis may be possible earlier. Three months is appropriate for children. To be included, the symptoms must have begun or have been significantly altered after the onset of this illness. It is unlikely that a patient will suffer from all symptoms in criteria 5 and 6. The disturbances tend to form symptom clusters that may fluctuate and change over time. Children often have numerous prominent symptoms but their order of severity tends to vary from day to day. *There is a small number of patients who have no pain or sleep dysfunction, but no other diagnosis fits except ME/CFS. A diagnosis of ME/CFS can be entertained when this group has an infectious illness type onset.

**Some patients have been unhealthy for other reasons prior to the onset of ME/CFS and lack detectable triggers at onset and/or have more gradual or insidious onset. Exclusions: Exclude active disease processes that explain most of the major symptoms of fatigue, sleep disturbance, pain, and cognitive dysfunction. It is essential to exclude certain diseases, which would be tragic to miss: Addison’s disease, Cushing’s Syndrome, hypothyroidism, hyperthyroidism, iron deficiency, other treatable forms of anemia, iron overload syndrome, diabetes mellitus, and cancer. It is also essential to exclude treatable sleep disorders such as upper airway resistance syndrome and obstructive or central sleep apnea; rheumatological disorders such as rheumatoid arthritis, lupus, polymyositis and polymyalgia rheumatica; immune disorders such as AIDS; neurological disorders such as multiple sclerosis (MS), Parkinsonism, myasthenia gravis and B12 deficiency; infectious diseases such as tuberculosis, chronic hepatitis, Lyme disease, etc.; primary psychiatric disorders and substance abuse. Exclusion of other diagnoses, which cannot be reasonably excluded by the patient’s history and physical examination, is achieved by laboratory testing and imaging. If a potentially confounding medical condition is under control, then the diagnosis of ME/CFS can be entertained if patients meet the criteria otherwise.

Co-Morbid Entities: Fibromyalgia Syndrome (FMS), Myofascial Pain Syndrome (MPS), Temporomandibular Joint Syndrome (TMJ), Irritable Bowel Syndrome (IBS), Interstitial Cystitis, Irritable Bladder Syndrome, Raynaud’s Phenomenon, Prolapsed Mitral Valve, Depression, Migraine, Allergies, Multiple Chemical Sensitivities (MCS), Hashimoto’s thyroiditis, Sicca Syndrome, etc. Such co-morbid entities may occur in the setting of ME/CFS. Others such as IBS may precede the development of ME/CFS by many years, but then become associated with it. The same holds true for migraines and depression. Their association is thus looser than between the symptoms within the syndrome. ME/CFS and FMS often closely connect and should be considered to be “overlap syndromes.” Idiopathic Chronic Fatigue: If the patient has unexplained prolonged fatigue (6 months or more) but has insufficient symptoms to meet the criteria for ME/CFS, it should be classified as idiopathic chronic fatigue.

The Oxford Criteria
A very broadly defined criteria for diagnosing chronic fatigue illness of any cause, favoured by UK researchers particularly of the Wessley school.
As used in the PACE trial

Impairment of short-term memory and loss of powers of concentration,
– usually coupled with other [neurological and psychological] disturbances such as:
NB These should be asked for as symptoms. not tests, and do not have to be total or persistent for the whole period. These symptoms in (a – e) should be recorded, but am not necessary to make the diagnosis]
a) emotional liability [feeling easily upset by things that would not upset the participant, but the upset is brief and has usually gone within a few hours. and certainly by the next day]
b) nominal dysphasia [difficulty finding the right word]
c) disturbed sleep pattens [of any sort]
d) disequilibrium [A feeling of imbalance]

Fluctuations of symptoms
[NB The usual precipitation by ‘physical or mental exercise ” should be recorded, but is not necessary to meet criteria.]
usually precipitated by either physical or mental exercise

These symptoms should have been present for at least 6 months and should be ongoing.

There is no primary depressive illness present and no anxiety disorder/neurosis
[N.B. This means if any depressive or anxiety disorder is present. the London criteria are not met]

PACE Trial medical exclusions

Established medical conditions known to produce chronic fatigue

Psychiatric exclusions

Schizophrenia

Manic depressive (bipolar) illness

Substance misuse

Eating disorder

Proven organic brain disease

Other psychiatric disorders (including depressive illness‘ anxiety disorders‘ and hyperventilation syndrome) are not reasons for exclusion.

Myalgic Encephalomyelitis: International Consensus Criteria
Published July 2011
The most recent criteria, supported my a large group of international researchers, a refinement to the Canadian criteria.

A. Post-Exertional Neuroimmune Exhaustion (PENE pen׳-e)
Compulsory

This cardinal feature is a pathological inability to produce sufficient energy on demand with prominent symptoms primarily in the neuroimmune regions. Characteristics are:

Marked, rapid physical and/or cognitive fatigability in response to exertion, which may be minimal such as activities of daily living or simple mental tasks, can be debilitating and cause a relapse.

Pain
a. Headaches: e.g. chronic, generalized headaches often involve aching of the eyes, behind the eyes or back of the head that may be associated with cervical muscle tension; migraine; tension headaches
b. Significant pain can be experienced in muscles, muscle-tendon junctions, joints, abdomen or chest. It is non-inflammatory in nature and often migrates. e.g. generalized hyperalgesia, widespread pain (may meet fibromyalgia criteria), myofascial or radiating pain

Sleep Disturbance
a. Disturbed sleep patterns: e.g. insomnia, prolonged sleep including naps, sleeping most of the day and being awake most of the night, frequent awakenings, awaking much earlier than before illness onset, vivid dreams/nightmares
b. Unrefreshed sleep: e.g. awaken feeling exhausted regardless of duration of sleep, day-time sleepiness

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